Reprocessing of polyolefins Changes in Rheology and Reprocessing Case Studies

摘要

Plastics recyling has received significant attention within the past decade. Positive or negative, this attention has provided an impetus for the plastics industry to advance recycling technology. Polyethylen resins have been identified as primary materials for solid waste minimization and recycling. This paper is concerned with the effects of recycling on the rheological properties of high density polyethylene blow molding resins. Properties such as shear and elongational viscosity and elastic modulus are examined. The changes that have been observed are analyzed in terms of known degradation mechanisms such as chain scission and cross-linking, and their relationship to the Phillips and Ziegler-Natta catalyst systems. Case studies are used to illustrate the practical challenges faced by manufacturers who use recycled polyethylene, including discussions on rheological considerations in wood filled polymers and rotomolded structures.